Huaneng Power International said its first quarter net profits fell by almost 80% to US$34.6 million, the South China Morning Post reported. This compares to a net profit of US$171.7 million recorded in the first quarter of the previous year. The listed unit of China’s largest power producer China Huaneng Group said profit margins were hurt by rising coal costs and a government-mandated 21-month power tariff freeze implemented to control inflation. Huaneng Power International had previously warned that it would report a more than 50% decline in net profit. Analysts said China’s power sector is facing the worst operating environment since the late 1990s. Earlier media reports said 70% of local government-run power plants losing money in the first quarter of this year.